1. Technical Field
The invention relates to power take off systems for motor vehicles and more particularly to a modularized power takeoff system integrated into a vehicle's controller area network.
2. Description of the Problem
Utility and recreational vehicles are often advantageously supplied with auxiliary equipment powered by the vehicle. Such auxiliary equipment can be hydraulically powered, such as trash compacting equipment on refuse collection vehicles, pneumatically powered shop tools or electrically powered devices.
Auxiliary electrical equipment can include hand tools, light sources, medical instruments, computers, televisions, box fans, pumps and refrigerators. With regard to electrical equipment, it is generally cheaper to equip vehicles with conventional alternating current (A.C.) appliances rather than adapt appliances for operation off of vehicle 12 volt direct current (D.C.) power. Accordingly, vehicles requiring auxiliary electrical equipment have been provided with auxiliary electrical systems which, in North America, convert power from the vehicle's electrical system to 60 cycle, single phase A.C. electricity at 110 volts R.M.S. Of course, conversion of power to three phase 230 volt, or single phase 50 cycle power, are also possible.
Hydraulic and pneumatic devices require a pump to pressurize a working fluid. These pumps may be a pump used for another system such as a power steering pump on an air brake system pump, but they are typically dedicated, special purpose pumps driven by the engine or a transmission mounted “power take off” (PTO) pump.
Special purpose auxiliary equipment which translates vehicle output to operate equipment supports PTO operation. Generally PTO operation has been enabled at the election of the driver or operator through specialized operator controls. Vehicles equipped for PTO operation can sometimes demand increased engine output. It would be advantageous to fully integrate control functions and engine management for PTO operation for ancillary equipment with existing vehicle control systems.
The demand for PTO support has generally been met with after market accessories. The integration of these accessories into increasingly complex vehicle systems is less than ideal. Nor have these accessories been as reliable, light weight, or small as possible, or conveniently provided as much power as can be required without modification of a vehicle's hardware.